Immunological aspects of psoriasis. II. Dissociated impairment of thymus-dependent lymphocytes.

We have investigated lymphocyte subpopulations (six different markers) and T cell functions (mitogen responses and serum thymic factor determination) in twenty patients with psoriasis compared with thirty-five healthy subjects. Normal results were found for B cell markers, but significantly lower numbers of T cells were assessed by E-rosettes and anti HTLA serum. Mitogen responses were significantly higher in psoriasis than in normal subjects of the same age. These findings could be in favour of a T cell subpopulation defect involved in an auto-immune pathogenesis of psoriasis.